When driving small motors, mechanical tolerances and hysteresis effects, as well as magnetic circuit variations, can cause offset in the motor start-of-travel (or home) position and reduced range of travel. These home position offsets and range of travel limitations vary from motor to motor. Thus, precise linear motion control of such motors may be difficult to achieve without some type of calibration.
In some positioning applications, the microcontroller or processor that issues the drive signal (i.e., position) requests also performs a calibration routine. The calibration routine may use output signal data from a number of different components, including a position sensor, to compensate for offset and range of travel differences. The microcontroller must store and subsequently use the calibration data to compute position request values. This type of calibration requires processing time and an allocation of memory space.